Fighting has been raging for more than a week in Pakistan's Bajaur tribal agency as militants surge back into the region from safe havens across the border in Afghanistan.

Just a year ago this area was declared free of insurgents. That was after a three-year military operation that Islamabad hailed as a major success in its strategy of clearing, holding, and developing militant-plagued regions of the Federally Administered Tribal Area (FATA).

Now, as calls are made for similar operations elsewhere in northwestern Pakistan, the resumption of fighting in Bajaur is raising questions about how effective the strategy really is when safe havens can easily be found across the border in Afghanistan.

The thousands of villagers fleeing the fighting for the safety of Bajaur's main town of Khar tell of relatives and neighbors struck down in the cross-fire.

"I asked my father, 'Why you are going back?' He said, 'We left our doors open, so I am going back to shut them.' And he said one of our relatives, named Mujahid, was shot dead and there weren't enough people at home to dig graves," says Farooq Shah of the village of Batwar, in Bajaur's Salarzai district

"But when he got back to our house to lock it, the shooting started and he was hit."

Pakistani Taliban insurgents attacked security checkpoints and seized Batwar after crossing over from Afghanistan's Konar Province on August 26.

Girls sit amid the rubble of their destroyed school near the Afghan border, which was allegedly bombed by the Taliban militants in Bajaur in April.

Azam Khan, another Batwar resident, says the militants told them to leave. "When the Taliban came to the area, and the army arrived too, the Taliban told us to leave quickly to avoid damage," he says. "So we left without taking anything. We don't even have blankets or clothes. We left with nothing."

Shoukat Ullah, Pakistan's federal minister in charge of FATA and the border regions, says the fighting has virtually emptied Batwar and its surrounding area. "More than 2,000 families have left the area so far. Each family from that area has many members, so it means many people are affected," Ullah said, adding that they received shelter from other people in Bajaur.

Declaration Of Victory Premature

In recent days, security forces claim to have cleared most parts of Batwar of militants but pockets of resistance remain.

How many militants are involved in the fighting is not known. The military has reported dozens of militants killed over the past 12 days, suggesting there could be hundreds of fighters. It has also reported injuries, but no deaths, among Pakistani troops and local tribal fighters known as "peace lashkars" opposed to the Taliban. The official casualty figures cannot be independently verified.

According to the military, all of the militants are members of the Tehreek-e Taliban Pakistan (TTP) -- the same group Islamabad announced in August 2011 was fully evicted from Bajaur. At the time, the government urged hundreds of thousands of residents who had fled the three years of fighting in Bajaur to return home. To ensure that they did, officials threatened to cut off the aid they received at displaced-persons camps.

But now the TTP's reappearance suggests that it used its eviction as an opportunity to regroup and recruit new fighters. The TTP recruits across Pakistan and includes members of multiple ethnic groups who are bound together by a fundamentalist interpretation of Islam and a goal of toppling the government and imposing strict Shari'a law.

The TTP's use of safe havens in Afghanistan mirrors the Afghan Taliban's successful use of safe havens in Pakistan. The two groups are believed to help each other but to fight only for themselves. No Afghan Taliban groups are reported to be taking part in the Bajaur combat.

Pakistani journalist Rahimullah Yusufzai, an expert on FATA based in Peshawar, says the resurgence of fighting in Bajaur shows how mixed the results of Pakistan's military sweep operations can be. He says the strategy has so far been only been successful in two areas. Both are far from the Afghan border.

"They haven't had a full victory yet. The Pakistani Army has had some success against the Taliban in Swat and in Malakand district [of Khyber Pakhtunkhwa Province] -- now there is no presence of the Taliban in those areas. And even if the Taliban want to come back to those areas, they won't be able to come openly," Yusufzai says. "But in my opinion, it's a very long war and it will be very difficult to achieve full victory."

Near the border, security forces have the upper hand in weaponry, including tanks and artillery, to pound militant hideouts in the mountainous region. But the militants' ability to melt across the border to safety gives them a tactical advantage. They can disappear and reappear at will and choose when and where to fight.

Written by Charles Recknagel, based on reporting by RFE/RL Radio Mashaal correspondents Shahnawaz Tarakzai in Bajaur and Siraj Zaheer in Islamabad